FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
“AN AGRICULTURAL BIOSTIMULANT/BIOFERTILIZER COMPOSITION”
Applicant name and Address:
NATURAL PLANT PROTECTION LIMITED of UPL LTD,
UNIPHOS HOUSE, MADHU PARK, C.D.MARG, KHAR W, MUMBAI
400052, INDIA
Nationality: IN
The following specification particularly describes the invention and the manner in which it is to be performed.
1

Field of invention:
The present disclosure relates to an agricultural composition comprising a biological extract.
In particular, the present disclosure relates to an agricultural composition comprising yeast
extracts and methods of preparing the same. More particularly, the present disclosure relates to
5 a biostimulant/biofertilizer composition.
Background:
Yeast extracts — the interior components of the yeast cell — are rich in a wide variety of amino
acids, which can complex with trace minerals for improved nutrient bioavailability. Yeast
extract is also known to be rich in nucleotides, sugars and a variety of trace minerals and
10 metabolites apart from amino acids and proteins.
Yeast-based biostimulants such as yeast extracts, yeast-derived amino acids and fertilizers have
been used to improve plant growth and yield, improve stress tolerance, and reduce the effects
of abiotic stresses in plants. Recently, the PCT publication WO2022184820A1 teaches
reducing the effects of abiotic stress in a plant and/or a plant part; and/or increasing the
15 tolerance to abiotic stress of a plant and/or a plant part; and/or increasing biomass or yield of a
plant and/or a plant part under abiotic stress; wherein said method comprises contacting the plant and/or the plant part or soil with a composition comprising a yeast-derived material. The yeast derived material may be a yeast hydrolysate, particularly obtained using an alkaline hydrolysis method.
20 Humic and fulvic acids which are organic acids found naturally in soil from the decomposition
of plant, animal and microbial residues. Fulvic and humic acid increase soil water retention. They also help to filter out toxins and heavy metals, increasing the health of the plant and its produce. These contribute to soil fertility, root nutrition, nutrient uptake, increases chlorophyll, and photosynthesis etc.
25 Sabreen Kh. A. Ibraheim (“Effect of Foliar Spray With Some Biostimulants on Growth, Yield
and Seeds Quality of Pea Plants Grown In Sandy Soil”, Journal of Applied Sciences Research (2014), 10(5), 400-407) compared the effects of foliar spraying of pea plants with yeast extract with that of biostimulant Mega Power – X comprising humic acid, fulvic acid, free amino acids, chelated minerals and potassium citrate.
2

Despite the knowledge about yeast-based biostimulants, there still exists immense potential to
optimize and develop new compositions based on yeast extracts which will improve yield
significantly, reduce the deleterious effects of biotic and abiotic stresses, and increase the
tolerance of plant towards these stresses. There also exists a need for new and innovative
5 biostimulant compositions which also function as a biofertilizer. There exists an unmet need in
the art to optimize the process of production of yeast-based plant growth promoter which will provide enhanced efficacy as a biostimulant and a biofertilizer. Moreover, there still remains a need for yeast extract-based compositions which can be applied in low doses to generate higher yield, growth, and stress tolerance in plants.
10 The present disclosure aims to provide compositions and methods that are markedly different
from such compositions known in the prior art and provide new and effective ways of improving yield and mitigating biotic and abiotic stress. The inventors of the present disclosure herein aim to provide a yeast-based agricultural composition which benefits the plant in terms of yield, growth, and stress tolerance, even at lower doses. The present disclosure also aims to
15 provide an effective method of obtaining a functionally effective yeast extract which
contributes to the overall efficacy of the agricultural compositions mentioned herein.
Summary:
An aspect of the present disclosure provides an agricultural composition comprising:
a. a yeast-based plant growth promoter;
20 b. a metabolic cofactor selected from B group of vitamins, ascorbic acid, or combinations
thereof; and c. a chelating agent selected from humic acid, fulvic acid, or combinations thereof.
An aspect of the present disclosure provides an agricultural composition comprising:
a. a yeast-based plant growth promoter;
25 b. a metabolic cofactor selected from B group of vitamins, ascorbic acid, or combinations
thereof;
c. a chelating agent selected from humic acid, fulvic acid, or combinations thereof; and
d. optionally, one or more additional plant growth promoters, macronutrients, or
micronutrients.
3

In an embodiment, the yeast-based plant growth promoter is a yeast extract, an inactive yeast,
yeast cell walls or yeast cell-wall derivatives. In an embodiment, the yeast extract is a cell-free
fermentation extract, cell-free spent media, yeast hydrolysate, cell-free yeast hydrolysate, yeast
autolysate, cell-free yeast autolysate, fermentation extract comprising live or dead cells, spent
5 media comprising live or dead cells, or an unfiltered extract comprising lysed cells and cell
debris.
In an embodiment, the yeast-based plant growth promoter is a yeast extract, obtained through
an alkaline hydrolysis, an enzymatic hydrolysis, an acid hydrolysis, a physical treatment, a
mechanical treatment, or combinations thereof. Preferably, the yeast extract is obtained through
10 a combination of processes comprising an enzymatic hydrolysis, an acid hydrolysis, and an
alkaline hydrolysis.
In an embodiment, yeast-based plant growth promoter is characterized by presence of amino
acids in the range of about 1% w/w to about 20% w/w of the total weight of the yeast-based
plant growth promoter. In an embodiment, the yeast-based plant growth promoter further
15 comprises carbohydrates, sugars, metabolites, and moisture.
In an aspect, there is provided a process of preparing the yeast-based plant-growth promoter, in particularly a yeast extract. In an embodiment, said yeast extract is obtained by a process comprising the following steps:
i) providing an inoculum of yeast;
20 ii) subjecting the yeast to a treatment with a hydrolyzing enzyme;
iii) subjecting the above mixture to a treatment with an acid followed by sedimentation;
iv) separating the supernatant and subjecting the sediment to a treatment with an alkali
solution followed by sedimentation,
v) blending the supernatants of step iv) to obtain said yeast extract.
25 Another aspect of the present disclosure provides a method of mitigating stress and increasing
yield in a plant and/or a plant part comprising applying to the plant, a plant part, or a locus an agricultural composition comprising:
a. a yeast-based plant growth promoter;
b. a metabolic cofactor selected from B group of vitamins, ascorbic acid, or combinations
30 thereof;
4

c. a chelating agent selected from humic acid, fulvic acid, or combinations thereof; and
d. optionally, one or more additional plant growth promoters, macronutrients or
micronutrients.
Another aspect of the present disclosure provides a use of an agricultural composition for
5 mitigating stress in a plant and/or a plant part, wherein said composition comprises:
a. a yeast-based plant growth promoter;
b. a metabolic cofactor selected from B group of vitamins, ascorbic acid, or combinations
thereof;
c. a chelating agent selected from humic acid, fulvic acid, or combinations thereof; and
10 d. optionally, one or more additional plant growth promoters, macronutrients or
micronutrients.
Detailed description
For the purposes of the following detailed description, it is to be understood that the invention
may assume various alternative variations and step sequences, except where expressly
15 specified to the contrary. Moreover, other than in any operating examples, or where otherwise
indicated, all numbers expressing, for example, quantities of materials/ingredients used in the specification are to be understood as being modified in all instances by the term "about".
Unless otherwise stated, all exact values provided herein are representative of corresponding approximate values (e.g., all exact exemplary values provided with respect to a particular factor
20 or measurement can be considered to also provide a corresponding approximate measurement,
modified by "about," where appropriate). As used herein, the term "about" refers to a measurable value such as a parameter, an amount, a temporal duration, and the like and is meant to include variations of +/-15% or less, specifically variations of +/-10% or less, more specifically variations of +/-5% or less, even more specifically variations of +/-1% or less, and
25 still more specifically variations of +/-0.1% or less of and from the particularly recited value,
in so far as such variations are appropriate to perform in the disclosure described herein.
Recitation of ranges of values are merely intended to serve as a shorthand method of referring
individually to each separate value falling within the range, unless otherwise indicated herein,
and each separate value is incorporated into the specification as if it were individually recited
30 herein. All provided ranges of values are intended to include the end points of the ranges, as
5

well as values between the end points, and are independently combinable. As used herein, all
numerical values or numerical ranges include integers within such ranges and fractions of the
values or the integers within ranges unless the context clearly indicates otherwise. Thus, for
example, reference to a range of 90-100%, includes 91%, 92%, 93%, 94%, 95%, 95%, 97%,
5 etc., as well as 91.1%, 91.2%, 91.3%, 91.4%, 91.5%, etc., 92.1%, 92.2%, 92.3%, 92.4%,
92.5%, etc., and so forth. All methods described herein can be performed in a suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.
It must be noted that, as used in this specification, the singular forms “a,” “an” and “the” include
singular and plural referents unless the content clearly dictates otherwise. The terms
10 “preferred” and “preferably” refer to embodiments of the invention that may afford certain
benefits, under certain circumstances.
As used herein, the terms “comprising” “including,” “having,” “containing,” “involving,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to.
The term “plant” or “target plant” as used herein refers to any vegetation to which the
15 compositions of the present disclosure can be applied for any purposes or any treatment. The
term covers a whole plant or a part thereof, such as stems, branches, bark, pistils, flowers,
petals, sepals, roots, rhizomes, buds, bulbs, tubers, petioles, nodes, internodes, leaves, leaflets,
meristems, root tips, shoot tips, fruits, reproductive organs such as anther, stamen, carpel,
ovary, style, stigma, and so forth. The term also covers seeds, seedlings, or any plant
20 propagation material.
The term "plant propagation material" is to be understood to denote all the generative parts of
the plant such as seeds and vegetative plant material such as cuttings and tubers (e. g. potatoes),
which can be used for the multiplication of the plant. This includes seeds, roots, fruits, tubers,
bulbs, rhizomes, shoots, sprouts and other parts of plants. Seedlings and young plants, which
25 are to be transplanted after germination or after emergence from soil, may also be included.
These plant propagation materials may be treated prophylactically with a plant protection compound either at or before planting or transplanting. In an embodiment, the term includes agronomically useful plants, for example for example vegetable, fruit and cereal crops, and ornamental plants.
30 The term “locus” as used herein shall denote the vicinity of the target plant in which growth
stimulation is desired. The locus includes the vicinity of the target plant which has either
6

emerged or is yet to emerge. The term “target plant” shall include a multitude of desired crop plants or an individual crop plant growing at a locus. The said locus includes the area, medium and soil where the target plant grows.
The term “biostimulant” as used herein refers to a product, ingredient, or a composition which
5 when applied to a plant and/or a part thereof results in a positive change or any improvement
in plant health, phenotypic or genotypic characteristics of a plant; visible beneficial changes in a plant; improvement in plant stress and disease tolerance; and improvement in yield and quality of produce. Non-limiting examples of changes or improvement effected by a biostimulant include: Improved plant nutrient use efficiency; Enhanced root and shoot growth;
10 Improved reproductive heat stress tolerance; Improved drought tolerance; Improved pollen
tube growth; Enhanced pollen viability; Increased fertilization and fruit set; Increased floral inflorescence primordia; Increased number of buds, pods and yield; Improved and strong root mass and architecture; Improved/increased bud development; Accelerated shoot or bud emergence; Enhanced vigor/uniformity of emergence; Improved and increased branching;
15 Improved/increased diameter and strength; Improved/increased inter-node length; Increase in
number of yield structures (ears, fruits etc); Increase in leaf area; Increased amount of chlorophyll, greening; Increased photosynthesis activity; Increase in CO2 fixation; Accelerated and improved flowering; Improvement in pollination; Enhanced fruit set & retention; Improvement in cell division for size and quality potential; Improvement in fruit finish;
20 Freedom from pest such as fungal pests, viruses, bacteria, weeds, insects, nematodes; Enhanced
resistance against pest such as fungal pests, viruses, bacteria, weeds, insects, nematodes; Increased plant weight; Increased plant height; Increased biomass such as higher overall fresh weight; Higher grain yield; More tillers; Larger leaves; Increased shoot growth; Increased protein content; Increased oil content; Increased starch content; Increased pigment content;
25 Increased plant vigor; Improved vitality of the plant; Improved plant growth; Improved plant
development; Improved visual appearance of the plant or a part thereof; Improved plant stand (less plant verse/lodging); Improved emergence; Enhanced nodulation, in particular rhizobial nodulation; Bigger leaf blade; Increased yield when grown on poor soils or unfavorable climate; Enhanced pigment content (e.g. Chlorophyll content); Earlier flowering; Earlier
30 fruiting; Earlier and improved germination; Earlier grain maturity; Improved self-defence
mechanisms; Improved stress tolerance and resistance of the plants against biotic and abiotic stress factors such as fungi, bacteria, viruses, insects, heat stress, cold stress, drought stress, UV stress and/or salt stress; Less non-productive tillers; Less dead basal leaves; Less input
7

needed (such as fertilizers or water); Greener leaves; Complete maturation under shortened
vegetation periods; Less fertilizers needed; Less seeds needed; Easier harvesting; Faster and
more uniform ripening; Longer shelf-life; Longer panicles; Delay of senescence; Stronger
and/or more productive tillers; Better extractability of ingredients; Improved quality of seeds
5 (for being seeded in the following seasons for seed production); Reduced production of
ethylene and/or the inhibition of its reception by the plant; Increased nutrient content; Increased
content of fatty acids; Increased metabolite content; Increased carotenoid content; Increased
sugar content; Increased amount of essential amino acids Improved nutrient composition;
Improved protein composition; Improved composition of fatty acids; Improved metabolite
10 composition; Improved carotenoid composition; Improved sugar composition; Improved
amino acids composition; Improved or optimal fruit color; Improved leaf color; Higher storage capacity; and/or Higher processability of the harvested products.
Thus, before describing the present disclosure in detail, it is to be understood that this invention is not limited to particularly exemplified process parameters or composition that may of course,
15 vary. It is also to be understood that the terminology used herein is for the purpose of describing
embodiments of the invention only and is not intended to limit the scope of the invention in any manner. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various
20 embodiments given in this specification. Unless otherwise defined, all technical and scientific
terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the case of conflict, the present document, including definitions will control.
An embodiment of the present disclosure provides an agricultural composition comprising:
25 a. a yeast-based plant growth promoter;
b. a metabolic cofactor selected from B group of vitamins, ascorbic acid, or combinations
thereof; and
c. a chelating agent selected from humic acid, fulvic acid, or combinations thereof.
In an embodiment, said composition further comprises one or more additional plant growth
30 promoters, macronutrients, micronutrients, or combinations thereof, wherein the additional
plant growth promoter is not a yeast-based plant growth promoter.
8

An embodiment of the present disclosure provides an agricultural composition comprising:
a. a yeast-based plant growth promoter;
b. a metabolic cofactor selected from B group of vitamins, ascorbic acid, or combinations
thereof;
5 c. a chelating agent selected from humic acid, fulvic acid, or combinations thereof; and
d. optionally, one or more additional plant growth promoters, macronutrients, micronutrients, or combinations thereof.
In an embodiment, the yeast-based plant growth promoter belongs to (derived from) a yeast
selected from the genera Saccharomyces, Kluyveromyces, Hanseniaspora, Metschnikowia,
10 Pichia, Starmerella, Torulaspora, Brettanomyces, Lachancea, Schizosaccharomyces or
Candida. Preferably, the yeast-based plant growth promoter belongs to a yeast of the genus Saccharomyces. More preferably, the yeast-based plant growth promoter belongs to the yeast Saccharomyces cerevisiae.
In an embodiment, the yeast-based plant growth promoter is a yeast extract, an inactive yeast,
15 yeast cell walls or yeast cell-wall derivatives. In a preferred embodiment, the yeast-based plant
growth promoter is a yeast extract.
In an embodiment, the yeast extract is a cell-free fermentation extract, cell-free spent media,
yeast hydrolysate, cell-free yeast hydrolysate, yeast autolysate, cell-free yeast autolysate,
fermentation extract comprising live or dead cells, spent media comprising live or dead cells,
20 or an unfiltered extract comprising lysed cells and cell debris. In a preferred embodiment, the
yeast extract is a cell-free yeast hydrolysate.
In an embodiment, the yeast-based plant growth promoter is a yeast extract obtained through
an alkaline hydrolysis, an enzymatic hydrolysis, an acid hydrolysis, a physical treatment, a
mechanical treatment, or combinations thereof. Preferably, the yeast extract is obtained through
25 a combination of processes comprising an enzymatic hydrolysis, an acid hydrolysis, and an
alkaline hydrolysis.
Thus, in a preferred embodiment, the yeast-based plant growth promoter is a yeast extract, wherein the yeast extract is obtained through a combination of processes comprising an enzymatic hydrolysis, an acid hydrolysis, and an alkaline hydrolysis.
9

In another preferred embodiment, the yeast-based plant growth promoter is a yeast extract, wherein the yeast extract is a cell-free yeast hydrolysate obtained through a combination of processes comprising an enzymatic hydrolysis, an acid hydrolysis, and an alkaline hydrolysis.
In an embodiment, the B group vitamin is selected from thiamine, riboflavin, niacin,
5 pantothenic acid, pyridoxine, biotin, folate, cyanocobalamine or derivatives thereof.
In an embodiment, the metabolic co-factor is a B group vitamin selected from thiamine,
riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folate, cyanocobalamine or derivatives
thereof. In a specific embodiment, the B group vitamin is pyridoxine or derivatives thereof. In
a specific embodiment, the B group vitamin is thiamine or derivatives thereof. In a specific
10 embodiment, the B group vitamin is riboflavin or derivatives thereof.
In an embodiment, the metabolic co-factor is ascorbic acid.
In an embodiment, the metabolic co-factor is a combination of one or more B group vitamins and ascorbic acid.
In an embodiment, the chelating agent is humic acid. In an embodiment, the chelating agent is
15 fulvic acid. In an embodiment, the chelating agent is a combination of humic acid and fulvic
acid.
In an embodiment, the additional plant growth promoter is one or more amino acids, L-amino
acids, or derivatives thereof. Thus, in an embodiment, the composition of the present disclosure
further comprises one or more additional amino acid(s), macronutrients, micronutrients, or
20 combinations thereof. In an embodiment, said composition comprises one or more additional
amino acid(s). In an embodiment, said composition comprises one or more additional macronutrients. In an embodiment, said composition comprises one or more additional micronutrients. In a preferred embodiment, said composition comprises one or more additional amino acid(s), micronutrients, and macronutrients.
25 In an embodiment, the macronutrients or micronutrients are added to the composition of the
present disclosure as inorganic salts. In an embodiment, the macronutrients or micronutrients may be selected from nitrogen or salts thereof, phosphorus or salts thereof, potassium or salts thereof, zinc or salts thereof, magnesium or salts thereof, manganese or salts thereof, boron or salts thereof, calcium or salts thereof, iron or salts thereof, or combinations thereof. In an
10

embodiment, zinc or salts thereof is in form of zinc sulphate heptahydrate. In an embodiment,
magnesium or salts thereof is in form of magnesium sulphate. In an embodiment, manganese
or salts thereof is in form of manganous chloride. In an embodiment, boron or salts thereof is
in form of boric acid. In an embodiment, calcium or salts thereof is in from of calcium chloride.
5 In an embodiment, iron or salts thereof is in form of ferrous sulphate. In a preferred
embodiment, the additional macronutrients or micronutrients may be selected from zinc sulphate heptahydrate, magnesium sulphate, manganous chloride, boric acid, calcium chloride, ferrous sulphate, or combinations thereof.
In an embodiment, the macronutrients or micronutrients may be present in the composition in
10 a chelated form.
In an embodiment, said additional plant growth promoter is an amino acid, an L-amino acid,
or derivatives thereof. In an embodiment, the amino acid or L-amino acid may be selected from
lysine, glycine, aspartic acid, alanine, tryptophan, proline, isoleucine, histidine, leucine,
threonine, glutamic acid, tyrosine, serine, glutamine, phenylalanine, cysteine, valine,
15 asparagine, arginine, sarcosine, L-lysine, L-glycine, L-aspartic acid, L-alanine, L-tryptophan,
L-proline, L-isoleucine, L-histidine, L-leucine, L-threonine, L-glutamic acid, L-tyrosine, L-serine, L-glutamine, L-phenylalanine, L-cysteine, L-valine, L-asparagine, L-arginine, L-sarcosine, or combinations thereof. In an embodiment, the amino acid or L-amino acid may be derived from a synthetic source or a natural source.
20 In an embodiment, the yeast-based plant growth promoter is present in the composition in an
amount ranging from about 1% w/w to about 90% w/w of the total weight of the composition. In an embodiment, the yeast-based plant growth promoter is present in the composition in an amount ranging from about 10% w/w to about 90% w/w of the total weight of the composition. In an embodiment, the yeast-based plant growth promoter is present in the composition in an
25 amount ranging from about 30% w/w to about 90% w/w of the total weight of the composition.
In an embodiment, the yeast-based plant growth promoter is present in the composition in an amount ranging from about 50% w/w to about 90% w/w of the total weight of the composition. In a specific embodiment, the yeast extract is present in the composition in an amount ranging from about 50% w/w to about 80% w/w of the total weight of the composition.
30 In an embodiment, yeast-based plant growth promoter is characterized by presence of amino
acids in the range of about 1% w/w to about 20% w/w of the total weight of the yeast-based
11

plant growth promoter. In an embodiment, the yeast-based plant growth promoter further comprises carbohydrates, sugars, metabolites, and moisture.
In an embodiment, yeast-based plant growth promoter is characterized by presence of organic
carbon in the range of about 5% w/w to about 6% w/w of the total weight of the yeast-based
5 plant growth promoter.
In an embodiment, the metabolic co-factor is present in the composition in an amount ranging from about 0.01% w/w to about 30% w/w of the total weight of the composition.
In an embodiment, the chelating agent is present in the composition in an amount ranging from
about 0.1% w/w to about 50% w/w of the total weight of the composition. In an embodiment,
10 the chelating agent is present in the composition in an amount ranging from about 1% w/w to
about 50% w/w of the total weight of the composition.
In an embodiment, the one or more additional plant growth promoters, macronutrients or
micronutrients are present in the composition in an amount ranging from about 0% w/w to
about 50% w/w of the total weight of the composition. In an embodiment, the one or more
15 additional plant growth promoters, macronutrients or micronutrients are present in the
composition in an amount ranging from about 0.01% w/w to about 50% w/w of the total weight of the composition.
In an embodiment, the one or more macronutrients or micronutrients are present in the
composition in an amount ranging from about 0% w/w to about 30% w/w of the total weight
20 of the composition. In an embodiment, the one or more macronutrients or micronutrients are
present in the composition in an amount ranging from about 0.01% w/w to about 30% w/w of the total weight of the composition.
In an embodiment, the composition may further comprise one or more externally added amino
acids as additional plant growth promoter. The amino acids may be added externally in an
25 amount ranging from about 0% w/w to about 20% w/w of the total weight of the composition.
The amino acids may be added externally in an amount ranging from about 0.1% w/w to about 20% w/w of the total weight of the composition.
In any of the composition, methods, or uses of the invention of the present disclosure, the composition may further comprise an agriculturally acceptable carrier.
12

Thus, an embodiment of the present disclosure provides an agricultural composition comprising:
a. a yeast-based plant growth promoter obtainable by a combination of processes
comprising an enzymatic hydrolysis, an acid hydrolysis, and an alkaline hydrolysis;
5 b. a metabolic cofactor selected from B group of vitamins, ascorbic acid, or combinations
thereof;
c. a chelating agent selected from humic acid, fulvic acid, or combinations thereof; and
d. optionally, one or more additional plant growth promoters, macronutrients,
micronutrients, or combinations thereof.
10 In a preferred embodiment, the yeast-based plant growth promoter is a yeast extract. In another
preferred embodiment, the yeast-based plant growth promoter is a yeast extract, wherein the yeast extract is a cell-free yeast hydrolysate.
An embodiment of the present disclosure provides an agricultural composition comprising:
a. 1% w/w to about 90% w/w of a yeast-based plant growth promoter;
15
b. 0.01% w/w to about 30% w/w of a metabolic cofactor selected from B group of
vitamins, ascorbic acid, or combinations thereof;
c. 0.1% w/w to about 50% w/w of a chelating agent selected from humic acid, fulvic acid,
or combinations thereof; and
20
d. optionally, 0% w/w to about 50% w/w of one or more additional plant growth
promoters, macronutrients, micronutrients, or combinations thereof.
An embodiment of the present disclosure provides an agricultural composition comprising:
a. 1% w/w to about 90% w/w of a yeast-based plant growth promoter obtainable by a
combination of processes comprising an enzymatic hydrolysis, an acid hydrolysis, and
an alkaline hydrolysis;
25 b. 0.01% w/w to about 30% w/w of a metabolic cofactor selected from B group of
vitamins, ascorbic acid, or combinations thereof;
c. 0.1% w/w to about 50% w/w of a chelating agent selected from humic acid, fulvic acid,
or combinations thereof; and
d. optionally, 0% w/w to about 50% w/w of one or more additional plant growth
30 promoters, macronutrients, micronutrients, or combinations thereof.
13

The embodiments of the present disclosure also provide a process of preparing the yeast-based plant growth promoter, in particularly a yeast extract.
In an embodiment, there is provided a process of preparing a yeast extract comprising the following steps:
5 i) providing an inoculum of yeast;
ii) subjecting the yeast to a treatment with a hydrolyzing enzyme;
iii) subjecting the above mixture to a treatment with an acid followed by sedimentation;
iv) separating the supernatant and subjecting the sediment to a treatment with an alkali
solution followed by sedimentation,
10 v) blending the supernatants of step iv) to obtain said yeast extract.
In an embodiment, the yeast extract obtained by the process mentioned herein the embodiment of the present disclosure is a cell-free yeast hydrolysate.
In an embodiment, the hydrolyzing enzyme used can be selected from papain or proteolytic
enzymes such as pepsin, alcalase, and/or trypsin. In a preferred embodiment, the hydrolyzing
15 enzyme used is papain.
In an embodiment, the acid used in the process is an acid selected from lactic acid, citric acid, sulphuric acid, and hydrochloric acid. In a preferred embodiment, the acid is hydrochloric acid.
In an embodiment, the concentration of the acid ranges from 20% to 100 %, preferably 25% to
99%. In an embodiment, the concentration of the acid may be in the range of 28% to 36%. In
20 an embodiment, the concentration of the acid may be in the range of 78% to 98%.
In an embodiment, the alkali may be selected from sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, ammonia, or combinations thereof. In an embodiment, the preferred alkali is potassium hydroxide.
In an embodiment, the pH of the solution after the acid hydrolysis step is in a range of about
25 2.5 to 3.5. The pH of the solution after the alkaline hydrolysis is in a range of about 5.5 to 6.5.
The pH of the final composition is in a range of about 2.0 to 7.0, preferably 2.5 to 6.5, even more preferably 3.0 to 5.0. In a preferred embodiment, the pH of the composition of the present disclosure is in a range of about 3.0 to 4.0
14

The present disclosure further provides a yeast extract obtained by a process comprising the following steps:
i) providing an inoculum of yeast;
ii) subjecting the yeast to a treatment with a hydrolyzing enzyme;
5 iii) subjecting the above mixture to a treatment with an acid followed by sedimentation;
iv) separating the supernatant and subjecting the sediment to a treatment with an alkali
solution followed by sedimentation,
v) blending the supernatants of step iv) to obtain said yeast extract.
In an embodiment, the yeast extract obtained by the process mentioned herein the embodiment
10 of the present disclosure is a cell-free yeast hydrolysate.
An embodiment also provides a process of making the composition of the present disclosure. In an embodiment, the composition of the present disclosure is obtained by a process comprising the following steps:
i) providing a yeast-based plant growth promoter;
15 ii) optionally, adding one or more plant growth promoters, micronutrients and/or
macronutrients to said yeast extract and allowing the solution to settle;
iii) blending a chelating agent with the supernatant obtained from step ii);
iv) adding a metabolic co-factor selected from B group of vitamins, ascorbic acid or
combinations thereof to the mixture obtained in step iii) to obtain the final composition.
20 In an embodiment, the yeast-based plant growth promoter is a yeast extract obtained through
an alkaline hydrolysis, an enzymatic hydrolysis, an acid hydrolysis.
In an embodiment, said composition of the present disclosure is a biostimulant or a biofertilizer composition.
In an embodiment, said composition of the present disclosure is a biostimulant composition.
25 In an embodiment, said composition of the present disclosure is a biofertilizer composition.
In an embodiment, said composition of the present disclosure is a stress-mitigating agent for the plant and/or a plant part it is applied to.
15

In an embodiment, the present disclosure provides a composition for: reducing the effects of
abiotic stress in a plant and/or a plant part; increasing the tolerance to abiotic stress of a plant
and/or a plant part; and/or increasing biomass or yield of a plant and/or a plant part under
abiotic stress; wherein said method comprises contacting the plant and/or the plant part or soil
5 with the composition of the present disclosure. Contacting the plant and/or the plant part or the
soil with the composition of the present disclosure may thereby reduce the effects of abiotic stress in the plant and/or the plant part and/or increase the tolerance to abiotic stress of the plant and/or the plant part and/or increase biomass or yield of the plant and/or the plant part compared to an untreated plant and/or plant part.
10 In an embodiment, said composition is applied at about 50 ml/ha to about 500 ml/ha. In an
embodiment, said composition is applied at about 60 ml/ha to about 400 ml/ha. In an embodiment, said composition is applied at about 70 ml/ha to about 300 ml/ha. In an embodiment, said composition is applied at about 80 ml/ha to about 200 ml/ha. In an embodiment, said composition is applied at about 90 ml/ha to about 100 ml/ha. In a preferred
15 embodiment, said composition is applied at about 90 ml/ha to about 100 ml/ha.
In an embodiment, the present disclosure provides a method for: reducing the effects of abiotic
stress in a plant and/or a plant part; increasing the tolerance to abiotic stress of a plant and/or a
plant part; and/or increasing biomass or yield of a plant and/or a plant part under abiotic stress;
wherein said method comprises contacting the plant and/or the plant part or soil with the
20 composition of the present disclosure. Contacting the plant and/or the plant part or the soil with
the composition of the present disclosure may thereby reduce the effects of abiotic stress in the plant and/or the plant part and/or increase the tolerance to abiotic stress of the plant and/or the plant part and/or increase biomass or yield of the plant and/or the plant part compared to an untreated plant and/or plant part.
25 Another embodiment of the present disclosure provides a method of mitigating stress and
increasing growth and yield in a plant and/or a plant part comprising applying to a plant and/or a plant part or a locus an agricultural composition comprising:
a. a yeast-based plant growth promoter;
b. a metabolic cofactor selected from B group of vitamins, ascorbic acid, or combinations
30 thereof;
c. a chelating agent selected from humic acid, fulvic acid, or combinations thereof; and
16

d. optionally, one or more additional plant growth promoters, macronutrients or micronutrients.
Another embodiment of the present disclosure provides a use of an agricultural composition for mitigating stress in a plant and/or a plant part, wherein said composition comprises:
5 a. a yeast-based plant growth promoter;
b. a metabolic cofactor selected from B group of vitamins, ascorbic acid, or combinations
thereof;
c. a chelating agent selected from humic acid, fulvic acid, or combinations thereof; and
d. optionally, one or more additional plant growth promoters, macronutrients or
10 micronutrients.
In an embodiment, said abiotic stress may be high temperature, heat, drought, water stress, high light intensity, hail, cold temperature, freezing, chilling, salinity, ozone, or combinations thereof.
In any of the methods or uses of the present disclosure, said method or use may further comprise
15 separately, simultaneously or sequentially contacting the plant and/or the plant part with one
or more additional agricultural compound. In any of the methods or uses of the present disclosure, said method or use may further comprise simultaneously contacting the plant and/or the plant part with one or more additional agricultural compound.
The plants on which the compositions of the present disclosure can be used are agronomically
20 useful plants and/or a plant part, for example for example vegetable, fruit and cereal crops, and
ornamental plants. The agronomically useful plants and/or a plant part are angiosperms selected
from the group consisting of Apiaceae, Asteraceae, Brassicaceae, Chenopodiaceae,
Convolvulaceae, Cucurbitaceae, Fabaceae, Gramineae, Liliaceae, Polygonaceae, Rosaceae,
Solanaceae, Poaceae, the Vitaceae. Thus, in an embodiment, the target plant and/or a plant part
25 is selected from crops, cereals, fruits, vegetables, nuts, vines, nursery plants and flowers. In an
embodiment, non-limiting examples of target plant and/or a plant part include corn, cereals
such as rice, wheat, barley, rye, oat, sorghum, millet, triticale, buckwheat, etc.; cotton, soybean,
beet, row crops, legumes, grams, sugar cane, tobacco, etc.; oilseeds such as oilseed rape,
peanut/groundnut, rapeseed, sunflower, etc.; vegetables: solanaceous vegetables such as
30 eggplant, tomato, pimento, pepper, potato, etc., cucurbit vegetables such as cucumber,
pumpkin, zucchini, water melon, melon, squash, gourds, muskmelon, etc., cruciferous
17

vegetables such as radish, white turnip, horseradish, kohlrabi, cabbage, leaf mustard, broccoli,
cauliflower, brussels sprouts, kale, etc., asteraceous vegetables such as burdock, crown daisy,
artichoke, lettuce, etc, liliaceous vegetables such as green onion, onion, shallot, garlic, and
asparagus, ammiaceous vegetables such as carrot, parsley, celery, parsnip, leek, etc.,
5 chenopodiaceous vegetables such as spinach, swiss chard, etc., lamiaceous vegetables such as
Perilla frutescens, mint, basil, etc.; herbs and spices such as coriander, chamomile, cassia, catnip, clove, cumin, curry, cilantro, cinnamon, cardamom, dill, anise, juniper, lavender, parsley, rosemary, marigold, mustard, nutmeg, fennel, poppy, thyme, vanilla, saffron, poppy, sage, wintergreen, etc.; flowers, foliage plants, turf grasses, fruits: pome fruits such apple, pear,
10 quince, guava, etc, stone fleshy fruits such as peach, plum, nectarine, cherry, apricot, prune,
etc., citrus fruits such as orange, lemon, lime, grapefruit, mandarin, malta, kumquat, pummelo, tangerine, tangor, uniq, etc., nuts such as chestnuts, walnuts, hazelnuts, almond, pistachio, cashew nuts, macadamia nuts, pecan nut, cashew nut, hazel nut, pine nut, etc. berries such as caneberry, strawberry, blueberry, cranberry, blackberry, raspberry, coryberry, darrowberry,
15 dewberry, thornless berry, evergreen blackberry, himalayaberry, hullberry, lavacaberry,
loganberry, lowberry, lucretiaberry, mammoth blackberry, marionberry, mora, mures deronce, nectarberry, olallieberry, evergreen berry, phenomenalberry, rangeberry, ravenberry, rossberry, dewberry, tayberry, youngberry, zarzamora, aronia berry, currant, elderberry, barberry, gooseberry, honeysuckle, huckleberry, jostaberry, juneberry, lingonberry, salal,
20 seabuckthorn, bayberry, buffaloberry, chokecherry, maypop, mulberry, bearberry, bilberry,
cloudberry, muntries, partridgeberry, etc., grape, kaki fruit, kiwi fruit, olive, plum, banana, coffee, date palm, coconuts, papaya, persimmon, avocado, dragon fruit, pomegranate, lychee, jackfruit, pineapple, passionfruit, sapota, etc., trees other than fruit trees; tea, mulberry, flowering plant, trees such as ash, birch, dogwood, eucalyptus, Ginkgo biloba, lilac, maple,
25 Quercus, poplar, Judas tree, Liquidambar formosana, plane tree, zelkova, japanese arborvitae,
fir wood, hemlock, juniper, Pinus, Picea, and Taxus cuspidate, etc., other crops such as chive, day lily, Elegans hosta, Fritillaria, gojiberry, okra, pea, hops, beans, guar, radish, amaranth, jute, fenugreek, lentils, chickpea, artichoke, rhubarb, licorice, sweet potato, Dioscorea japonica, colocasia, ornamental grasses (lawn turf, sod, etc.), varieties and cultivars thereof.
30 The compositions of the present disclosure as per an embodiment can be applied
• Pre-emergence
• Post-emergence
• Before sowing
18

• Pre-harvest
• Post-harvest
In an embodiment, the compositions of the present disclosure are applied before
planting/sowing; at the time of sowing, germination, early leaf stage, early bloom stage, pre-
5 bloom stage, full bloom stage, petal fall stage, swollen bud stage, bud break stage, post petal
fall stage, post bud break stage, pre-bud break stage, full pistillate stage, post pollination stage,
square formation stage, pegging stage, post-pegging stage, fruit set stage, early mid-bloom,
greenup (post-dormancy) stage, bud set stage, etc; after flowering stage; harvest stage; and/or
post-harvest. In an embodiment, the compositions of the present disclosure may be applied
10 anytime throughout the growth stage as conventionally known to a person skilled in the art.
The time of application depends on the target plant; environmental conditions such as nutrient
deficiency, biotic and abiotic stresses; type of application and the expected outcome or any
other parameter known to a person skilled in the art. Applications can be made throughout the
growth of the plant, one or more times a week.
15 In an embodiment, the compositions of the present disclosure are applied directly and/or
indirectly to the plant and/or to plant propagation material by drenching the soil, by drip application onto the soil, by soil injection, by dipping or by treatment of seeds.
The compositions of the present disclosure may be applied by dusting, spraying, granular
application, seed pelleting/seed dressing, broadcasting, in furrow application, side dressing,
20 spot application, ring application, root zone application, pralinage, seedling root dip, sett
treatment, trunk/stem injection, padding, swabbing, root feeding, soil drenching, capsular placement, baiting, fumigation, banding, foliar application, basal application, space treatment, enclosed space fumigation and such other methods which may help prevent or control or eradicate the disease.
25 In a preferred embodiment, the compositions of the present disclosure are applied as a drench
application, in-furrow application, soil, drip irrigation, soil injection, hydroponic application, capillary action application, root infiltration, or a foliar application. In an embodiment, the compositions of the present disclosure is applied as a seed treatment such as seed soak application, seed coating application, germination treatment; or a rooting/shooting dip
30 treatment. The type of application is decided as per the target plant, the outcome expected, and
19

the time of application and any other conventional parameters as known to a person skilled in the art.
The compositions of the present disclosure can be applied by the use of conventional ground
sprayers, granule applicators, watering (drenching), drip irrigation, spraying, atomizing,
5 broadcasting, dusting, foaming, spreading-on, aerial methods of spraying, aerial methods of
application, methods utilizing application using modern technologies such as, but not limited to, drones, robots, predosage device, a knapsack sprayer, a spray tank, a spray plane, or an irrigation system and by other conventional means known to those skilled in the art.
In a further embodiment, the compositions of the present disclosure are combined with,
10 formulated with and/or applied with one or more additional agrochemically active substances.
According to an embodiment, the said agrochemically active substance is selected from
fertilizers, mycorrhiza, micronutrients, acaricides, algicides, antifeedants, avicides,
bactericides, bird repellents, chemosterilants, fungicides, herbicide safeners, herbicides, insect
attractants, insect repellents, insecticides, mammal repellents, mating disrbyrs, molluscicides,
15 nematicides, plant activators, plant-growth regulators, rodenticides, synergists, virucides,
derivatives thereof, biological control agents, superabsorbent polymers and mixtures thereof.
All headings and sub-headings are used herein for convenience only and should not be construed as limiting the invention in any way.
The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is
20 intended merely to better illuminate the invention and does not pose a limitation on the scope
of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Examples
Example 1: Production of yeast-based plant growth promoter, i.e. cell-free yeast
25 hydrolysate
A pure culture of Saccharomyces cerevisiae (MTCC accession no.: 25522) maintained by
lyophilization was used and working cultures were prepared from concentrated lyophilized
culture. Primary Seed inoculum of Saccharomyces cerevisiae was prepared using Malt extract,
Peptone, and Glucose in a flask. Contamination and growth were checked before inoculating
30 to prepare Secondary seed inoculum.
20

For fermentation specific growth media was prepared with Glucose, Malt extract, and Peptone, pH of the media was maintained at 6.5-7.0. The media was sterilized for 20 min. Prior to inoculation the media was cooled to room temperature and inoculated using Secondary seed inoculum of about 0.1% to 40% to the media volume through sterilized conditions into the flask/fermenter. The media temperature was maintained at room temperature for the growth phase. After 3 days of fermentation, the temperature of the broth was increased to 40-85°C and added with a hydrolase enzyme and agitated for 1-6 hours. After enzyme hydrolysis, the temperature was raised to 60-120°C to deactivate the enzyme and at the same temperature hydrochloric acid was added and agitated for 3-10 hours. Extracted broth was cooled down to room temperature and keep for settlement. Supernatant was transferred to another vessel and 5% Caustic potash solution was added to the sediment and the temperature was increased to 60-120°C, agitated for 3-10 hours. Extracted broth was cooled down to room temperature and keep for settlement. The supernatant of this step was blended with the supernatant of enzyme and acid hydrolysis followed by filtration with 0.1 – 3 mm filters to obtain clear cell-free yeast hydrolysate.
Example 2: Production of biofertilizer/biostimulant composition
The cell-free yeast hydrolysate thus obtained in Example 1 was used to prepare the composition of the present disclosure.
About 67% of cell-free yeast hydrolysate was fortified with inorganic salts such as Zinc
20 sulphate heptahydrate, Magnesium sulphate, Manganous chloride, Boric acid, Calcium
chloride, Ferrous sulphate. The blended mixture was allowed to settle, and supernatant was separated and blended with Fulvic acid 4% SL. The mixture was filtered. The filtrate was enriched with Vitamin B6, and Ascorbic acid. The final mixture was filtered to remove any undissolved material to obtain the composition of the present disclosure.
25 Table 1: Composition of yeast extract

Source Quantity in the formulation (% W/W)
Saccharomyces cerevisiae extract 67.17
Inorganic salts 9.9
Ascorbic acid 0.34
Pyridoxine HCl 0.19
Fulvic acid (AI 4% SL) 22.4
Total 100
21

Example 3: Production of biofertilizer/biostimulant composition enriched with amino acids
The cell-free yeast hydrolysate thus obtained in Example 1 was used to prepare the composition
5 of the present disclosure.
About 59% cell-free yeast hydrolysate was fortified with inorganic salts - Zinc sulphate
heptahydrate, Magnesium sulphate, Manganous chloride, Boric acid, Calcium chloride,
Ferrous sulphate. The blended mixture was allowed to settle, and supernatant was separated
and blended with Fulvic acid 4% SL. The mixture was filtered. The filtrate was enriched with
10 Vitamin B6, and Ascorbic acid. The mixture was enriched with 80% amino acid solution
comprising all 20 amino acids to obtain a final composition comprising total amino acid content in the range of about 12-15% w/w of the total weight of the composition. The final mixture was filtered to remove any undissolved material to obtain the composition of the present disclosure.
15 Table 2: Composition of yeast extract with amino acid powder

Source Quantity in the formulation (% W/W)
Saccharomyces cerevisiae extract 59.21
Inorganic salts 8.72
Ascorbic acid 0.39
Pyridoxine HCl 0.09
Fulvic acid (AI 4% SL) 19.74
Amino acid Powder (80%) 11.85
Total 100
Example 4: Production of biofertilizer/biostimulant composition
The cell-free yeast hydrolysate thus obtained in Example 1 was used to prepare the composition of the present disclosure.
About 75% cell-free yeast hydrolysate was fortified with inorganic salts - Zinc sulphate
20 heptahydrate, Magnesium sulphate, Manganous chloride, Boric acid, Calcium chloride,
Ferrous sulphate. The blended mixture was allowed to settle, and supernatant was separated and blended with Fulvic acid 4% SL. The mixture was filtered. The filtrate was enriched with Vitamin B6, and Ascorbic acid. The mixture was enriched with 80% amino acid solution
22

comprising all 20 amino acids to obtain a final composition comprising total amino acid content in the range of about 12-15% w/w of the total weight of the composition. The final mixture was filtered to remove any undissolved material to obtain the composition of the present disclosure.
5 Table 3: Composition of yeast extract with amino acids

Source Quantity in the formulation (% W/W)
Saccharomyces cerevisiae extract 75
Inorganic salts 2.65
Ascorbic acid 0.5
Pyridoxine HCl 0.1
Fulvic acid (AI 4% SL) 0.8
80% amino acids 12
Aqua Q.S.
Total 100
Example 5: Production of biofertilizer/biostimulant composition
The cell-free yeast hydrolysate thus obtained in Example 1 was used to prepare the composition of the present disclosure.
About 75% cell-free yeast hydrolysate was fortified with inorganic salts - Zinc sulphate
10 heptahydrate, Magnesium sulphate, Manganous chloride, Boric acid, Calcium chloride,
Ferrous sulphate. The blended mixture was allowed to settle, and supernatant was separated
and blended with Fulvic acid 4% SL. The mixture was filtered. The filtrate was enriched with
Vitamin B6, and Ascorbic acid. The mixture was enriched with 80% amino acid solution
comprising all 20 amino acids to obtain a final composition comprising total amino acid content
15 in the range of about 12-15% w/w of the total weight of the composition. The final mixture
was filtered to remove any undissolved material to obtain the composition of the present disclosure.
Table 4: Composition of yeast extract with amino acids

Source Quantity in the formulation (% W/W)
Saccharomyces cerevisiae extract 75
Inorganic salts 1.7
Ascorbic acid 0.5
Pyridoxine HCl 0.1
23

Fulvic acid (AI 4% SL) 0.8
80% amino acids 10
Aqua Q.S.
Total 100
Example 6: Production of biofertilizer/biostimulant composition
The cell-free yeast hydrolysate thus obtained in Example 1 was used to prepare the composition of the present disclosure.
About 75% cell-free yeast hydrolysate was fortified with inorganic salts - Zinc sulphate
5 heptahydrate, Magnesium sulphate, Manganous chloride, Boric acid, Calcium chloride,
Ferrous sulphate. The blended mixture was allowed to settle, and supernatant was separated and blended with Fulvic acid 4% SL. The mixture was filtered. The filtrate was enriched with Vitamin B6, and Ascorbic acid. The final mixture was filtered to remove any undissolved material to obtain the composition of the present disclosure.
10 Table 5: Composition of yeast extract

Source Quantity in the formulation (% W/W)
Saccharomyces cerevisiae extract 75
Inorganic salts 2.65
Ascorbic acid 0.5
Pyridoxine HCl 0.1
Fulvic acid (AI 4% SL) 0.8
Aqua Q.S.
Total 100
Example 7: Production of biofertilizer/biostimulant composition
The cell-free yeast hydrolysate thus obtained in Example 1 was used to prepare the composition of the present disclosure.
About 75% cell-free yeast hydrolysate was fortified with inorganic salts - Zinc sulphate
15 heptahydrate, Magnesium sulphate, Manganous chloride, Boric acid, Calcium chloride,
Ferrous sulphate. The blended mixture was allowed to settle, and supernatant was separated and blended with Fulvic acid 4% SL. The mixture was filtered. The filtrate was enriched with Vitamin B6, and Ascorbic acid. The final mixture was filtered to remove any undissolved material to obtain the composition of the present disclosure.
24

Table 6: Composition of yeast extract

Source Quantity in the formulation (% W/W)
Saccharomyces cerevisiae extract 75
Inorganic salts 1.7
Ascorbic acid 0.5
Pyridoxine HCl 0.1
Fulvic acid (AI 4% SL) 0.8
Aqua Q.S.
Total 100
Example 8: Production of biofertilizer/biostimulant composition
The cell-free yeast hydrolysate thus obtained in Example 1 was used to prepare the composition
5 of the present disclosure.
About 75% cell-free yeast hydrolysate was fortified with other ingredients such as inorganic
salts (Zinc sulphate heptahydrate, Magnesium sulphate, Manganous chloride, Boric acid,
Calcium chloride, Ferrous sulphate), Fulvic acid Vitamin B6, and Ascorbic acid. The cell-free
yeast hydrolysate was characterized by total amino acid content in the range of about 12% w/w
10 - 15% w/w and total organic carbon in the range of 5% w/w - 6% w/w of the total weight of
the yeast extract. The final mixture was filtered to remove any undissolved material to obtain the composition of the present disclosure.
Table 7: Composition of yeast extract

Source Quantity in the formulation (% W/W)
Saccharomyces cerevisiae extract Total amino acids Total organic carbon 75
(12.0-15.0)
(5.0-6.0)
Other ingredients Q.S.
Total 100
Example 9: Efficacy of composition of Example 4 on soybean
15 The composition of example 4 was applied on soybean and its effect on growth and
development of soybean was evaluated. A plot of 5m x 5m was planted with soybean with a spacing of 45cm x 5 cm. The experimental design contained 3 replicates of every treatment. 3
25

treatments of composition of example 4 were conducted at rates of 50 ml/ha, 75 ml/ha and 100 ml/ha. Each treatment included 2 applications of the composition, first application A at 10 days after sowing (DAS) and second application B at 25 DAS. For efficacy, following parameters were evaluated and compared with an untreated set of soybean plants:
5 a. Phytotoxicity (0-10 scale) : where 0=No phytotoxicity and 10=100% crop damage
(10DAA,10DAB)
b. Plant vigour (0-10 scale) : where 0=poor and 10=excellent (10DAA,10DAB)
c. Plant height at 10 DAB & at harvest (10 randomly selected, tagged plants per treatment)
d. No of flower/Pods/ plant at (10DAB & at harvest)
10 e. Seed yield kg per plot at harvest
f. Yield Q/ha
Table 8: Biostimulant effect of composition of example 4 on soybean plant growth and development

Treatment Use
rate
(ml/ha) Phytotoxicity Plant vigour (Visual) Plant Height (cm)

3DAA 7DAA 10DAA 10DAA 10DAB 10DAB At Harvest
Untreated 0 0 0 0 8 8 34.1 56.1
composition of example 4 50 0 0 0 9 9 35.2 58.2
composition of example 4 75 0 0 0 9 9 36.3 59.3
composition of example 4 100 0 0 0 10 10 37.7 60.9
Table 9: Biostimulant effect of composition of example 4 on soybean yield

Treatment Dose ml/ha No of Pods/plant at harvest Yield % yield increase

kg/25 sq.mt q/ha

Untreated 0 30.0 3.00 1200 0
composition of example 4 50 31.0 3.10 1240 3.3
composition of example 4 75 32.0 3.13 1252 4.3
composition of example 4 100 32.4 3.17 1268 5.7
26

From the above table, it can be observed that the composition of example 4 at 100 ml/ha showed excellent crop vigour, followed by more no. of pod/ plant and yield. The composition of example 4 at 100 ml/ha showed excellent incremental yield (5.7 %) compared to the untreated control.
5 Example 10: Efficacy of composition of Example 7 on soybean
The composition of example 7 was applied on soybean and its effect on growth and
development of soybean was evaluated. A plot of 5m x 2.5m was planted with soybean with a
spacing of 60cm row to row. The experimental design contained 4 replicates of every treatment.
3 treatments of composition of example 7 were conducted at rates of 50 ml/ha, 125 ml/ha and
10 150 ml/ha. Each treatment included 2 applications of the composition, first application at 17
days after sowing (DAS) and second application at 36 DAS. For efficacy, following parameters were evaluated and compared with an untreated set of soybean plants at 90DAS stage: number of branches and number of pods per plant.
Table 10: Biostimulant effect of composition of example 7 on soybean plant growth and yield

Treatment Dose ml/ha No. of branches per plant No. of pods per plant
Untreated - 6.1 63.7
composition of example 7 50 7.7 77.2
composition of example 7 125 8.0 80.1
composition of example 7 150 8.1 81.6
15 Example 11: Efficacy of yeast extract obtained by different processes.
Six types of yeast extract were prepared as per table 11 –
Table 11: Yeast extracts prepared by different methods

Extract 1 Fermented yeast extract (fermented and heat killed yeast – S. cerevisiae – to obtain an extract without hydrolysis steps)
Extract 2 Fermented yeast – enzyme hydrolyzed (Yeast extract obtained by a process as followed in Example 1, without acid and alkali hydrolysis)
Extract 3 Fermented yeast – acid hydrolyzed (Yeast extract obtained by a process as followed in Example 1, without enzyme and alkali hydrolysis)
27

Extract 4 Fermented yeast – alkali hydrolyzed (Yeast extract obtained by a process as followed in Example 1, without acid and enzyme hydrolysis)
Extract 5 Fermented yeast – enzyme, acid & alkali hydrolyzed (Yeast extract obtained by a process as followed in Example 1)
Extract 6 Fermented yeast – enzyme & acid hydrolyzed (Yeast extract obtained by a process as followed in Example 1, without alkali hydrolysis)
Pot trials of soybean were set up with 3 replicates for every treatment. The yeast extracts
(Extracts 1-6) were applied as foliar spray 10 days after transplanting the plants in pots (3-4
leaf stage), with a water spray volume of 500 L/ha, and at a rate of 0.5 ml/L. A second
application of the extracts was done 15 days after the first application. The plants were
5 evaluated for their leaf size (in terms of leaf area sq. cm) 15 days after second spray. The results
are presented below:
Table 12: Effect of yeast extracts of table 11 on soybean leaf growth

Treatment Leaf area Sq.cm -before spraying Leaf area Sq.cm -2nd spray - 15 days after spraying % increase in Leaf area Sq.cm after 2nd spray
Extract 1 0.114 1.450 1171.9
Extract 2 0.121 1.216 905.0
Extract 3 0.128 1.280 900.0
Extract 4 0.116 1.507 1199.1
Extract 5 0.143 2.022 1314.0
Extract 6 0.122 1.554 1173.8
From the above table, it is observed that an extract produced by the combination of enzyme
hydrolysis, acid hydrolysis and alkaline hydrolysis (Extract 5) produces wider and bigger
10 leaves than other extracts with 1314% increase in leaf size.
Example 12: Efficacy of yeast extract obtained by different processes.
Following treatment composition were prepared as shown in table 13:
Table 13: Treatment compositions

Treatment 1 0.5% w/w Ascorbic acid dissolved in water
Treatment 2 0.1% w/w Pyridoxine dissolved in water
Treatment 3 75% w/w Yeast extract of Example 1 + 0.5% w/w Ascorbic acid + 0.1% w/w Pyridoxine + Water Q.S.
Treatment 4 75% w/w Yeast extract of Example 1 + 0.8% w/w of 4% fulvic acid + Water Q.S.
Treatment 5 75% w/w Yeast extract of Example 1 + 2.65% inorganic salts (Zinc sulphate heptahydrate, Magnesium sulphate, Manganous
28

chloride, Boric acid, Calcium chloride, Ferrous sulphate) + Water Q.S.
Treatment 6 Composition of Example 6
Treatment 7 0.5% w/w Ascorbic acid + 0.1% w/w Pyridoxine + 0.8% w/w of 4% fulvic acid + 2.65% inorganic salts (Zinc sulphate heptahydrate, Magnesium sulphate, Manganous chloride, Boric acid, Calcium chloride, Ferrous sulphate) + Water Q.S.
Pot trials of soybean were set up with 3 replicates for every treatment. The treatments
(Treatment 1-7) were applied as foliar spray 10 days after transplanting the plants in pots (3-4
leaf stage), with a water spray volume of 500 L/ha, and at a rate of 0.5 ml/L. A second
application of the extracts was done 15 days after the first application. The plants were
5 evaluated for their leaf size (in terms of leaf area sq. cm) 15 days after second spray. The results
are presented below:
Table 14: Effect of treatment compositions of table 13 on soybean leaf growth

Treatment Leaf area Sq.cm -before spraying Leaf area Sq.cm -2nd spray - 15 days after spraying % increase in Leaf area Sq.cm after 2nd spray
Treatment 1 0.136 1.287 846.3235
Treatment 2 0.108 1.048 870.3704
Treatment 3 0.131 0.798 509.1603
Treatment 4 0.097 0.976 906.1856
Treatment 5 0.112 0.916 717.8571
Treatment 6 0.115 1.544 1242.609
Treatment 7 0.125 1.203 862.4
From the above table, it is observed that Treatment 6 show the highest efficacy with more than 1000% increase in leaf area.
10
29

We Claim:
1. An agricultural composition comprising:
(a) a yeast-based plant growth promoter;
(b) a metabolic cofactor selected from B group of vitamins, ascorbic acid, or 5 combinations thereof; and
(c) a chelating agent selected from humic acid, fulvic acid, or combinations thereof.
2. The agricultural composition of claim 1, wherein the composition further comprises
optionally one or more additional plant growth promoters, macronutrients,
micronutrients, or combinations thereof.
10 3. The agricultural composition of claim 1, wherein the yeast-based plant growth
promoter belongs to a yeast selected from the genera Saccharomyces, Kluyveromyces, Hanseniaspora, Metschnikowia, Pichia, Starmerella, Torulaspora, Brettanomyces, Lachancea, Schizosaccharomyces or Candida.
4. The agricultural composition of claim 3, wherein the yeast-based plant growth
15 promoter belongs to the yeast Saccharomyces cerevisiae.
5. The agricultural composition of claim 1, wherein the yeast-based plant growth promoter is a yeast extract, an inactive yeast, yeast cell walls or yeast cell-wall derivatives.
6. The agricultural composition of claim 5, wherein the yeast-based plant growth
20 promoter is a yeast extract selected from a cell-free fermentation extract, cell-free spent
media, yeast hydrolysate, cell-free yeast hydrolysate, yeast autolysate, cell-free yeast autolysate, fermentation extract comprising live or dead cells, spent media comprising live or dead cells, or an unfiltered extract comprising lysed cells and cell debris.
7. The agricultural composition of claim 5, wherein the yeast-based plant growth
25 promoter is a yeast extract obtained through a combination of processes comprising an
enzymatic hydrolysis, an acid hydrolysis, and an alkaline hydrolysis.
8. The agricultural composition of claim 1, wherein the B group vitamin is selected from
thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folate,
cyanocobalamine or derivatives thereof.
30

9. The agricultural composition of claim 2, wherein the additional plant growth promoter
is one or more amino acids, L-amino acids, or derivatives thereof.
10. The agricultural composition of claim 2, wherein the macronutrients or
micronutrients are added to said composition as inorganic salts selected from nitrogen or
5 salts thereof, phosphorus or salts thereof, potassium or salts thereof, zinc or salts thereof,
magnesium or salts thereof, manganese or salts thereof, boron or salts thereof, calcium or salts thereof, iron or salts thereof, or combinations thereof.
11. The agricultural composition of claim 1, wherein the yeast-based plant growth
promoter is present in the composition in an amount ranging from about 1% w/w to
10 about 90% w/w of the total weight of the composition.
12. The agricultural composition of claim 1, wherein the metabolic co-factor is present
in the composition in an amount ranging from about 0.01% w/w to about 30% w/w of the
total weight of the composition.
13. The agricultural composition of claim 1, wherein the chelating agent is present in the
15 composition in an amount ranging from about 0.1% w/w to about 50% w/w of the total
weight of the composition.
14. The agricultural composition of claim 2, wherein the optional one or more additional
plant growth promoters, macronutrients or micronutrients are present in the composition
in an amount ranging from about 0% w/w to about 50% w/w of the total weight of the
20 composition.
15. The agricultural composition of claim 1, wherein the yeast-based plant growth
promoter is a yeast extract prepared by a process comprising the following steps:
(i) providing an inoculum of yeast;
(ii) subjecting the yeast to a treatment with a hydrolyzing enzyme;
25 (iii) subjecting the above mixture to a treatment with an acid followed by
sedimentation; (iv) separating the supernatant and subjecting the sediment to a treatment with an
alkali solution followed by sedimentation, (v) blending the supernatants of step iv) to obtain said yeast extract.
31

5

16. A process of preparing the composition of claim 1 comprising the following steps: (i) providing a yeast-based plant growth promoter; (ii) optionally, adding one or more plant growth promoters, micronutrients and/or
macronutrients to said yeast extract and allowing the solution to settle; (iii) blending a chelating agent with the supernatant obtained from step ii); (iv) adding a metabolic co-factor selected from B group of vitamins, ascorbic acid or
combinations thereof to the mixture obtained in step iii) to obtain the final
composition.

17. A method of mitigating stress and increasing growth and yield in a plant and/or a
10 plant part comprising applying to a plant and/or a plant part or a locus an agricultural
composition of claim 1.